Commit 340b6e59 authored by Richard Alpe's avatar Richard Alpe Committed by David S. Miller
Browse files

tipc: fix broadcast wakeup contention after congestion 



commit 908344cd ("tipc: fix bug in multicast congestion handling")
introduced a race in the broadcast link wakeup functionality.

This patch eliminates this broadcast link wakeup race caused by
operation on the wakeup list without proper locking. If this race
hit and corrupted the list all subsequent wakeup messages would be
lost, resulting in a considerable memory leak.

Signed-off-by: default avatarRichard Alpe <richard.alpe@ericsson.com>
Signed-off-by: default avatarErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4f675eb2

net/tipc/link.c

+4 −4
Original line number Diff line number Diff line
@@ -293,7 +293,7 @@ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr, 
	l_ptr->next_out_no = 1;

	__skb_queue_head_init(&l_ptr->outqueue);

	__skb_queue_head_init(&l_ptr->deferred_queue);

	__skb_queue_head_init(&l_ptr->waiting_sks);

	skb_queue_head_init(&l_ptr->waiting_sks);



	link_reset_statistics(l_ptr);
@@ -358,7 +358,7 @@ static bool link_schedule_user(struct tipc_link *link, u32 oport, 
		return false;

	TIPC_SKB_CB(buf)->chain_sz = chain_sz;

	TIPC_SKB_CB(buf)->chain_imp = imp;

	__skb_queue_tail(&link->waiting_sks, buf);

	skb_queue_tail(&link->waiting_sks, buf);

	link->stats.link_congs++;

	return true;

}
@@ -378,8 +378,8 @@ static void link_prepare_wakeup(struct tipc_link *link) 
		if (pend_qsz >= link->queue_limit[TIPC_SKB_CB(skb)->chain_imp])

			break;

		pend_qsz += TIPC_SKB_CB(skb)->chain_sz;

		__skb_unlink(skb, &link->waiting_sks);

		__skb_queue_tail(&link->owner->waiting_sks, skb);

		skb_unlink(skb, &link->waiting_sks);

		skb_queue_tail(&link->owner->waiting_sks, skb);

	}

}

net/tipc/node.c

+1 −1
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ struct tipc_node *tipc_node_create(u32 addr) 
	INIT_LIST_HEAD(&n_ptr->list);

	INIT_LIST_HEAD(&n_ptr->publ_list);

	INIT_LIST_HEAD(&n_ptr->conn_sks);

	__skb_queue_head_init(&n_ptr->waiting_sks);

	skb_queue_head_init(&n_ptr->waiting_sks);

	__skb_queue_head_init(&n_ptr->bclink.deferred_queue);



	hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);

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